A palatal bar is a known orthodontic appliance which is used during initial treatment to reposition misaligned molar teeth by application of rotating, tipping or torquing forces. An equally important application is in stabilizing and maintaining molar teeth in an orthodontically correct position while the molars are used as force-reaction anchors during application of corrective forces for repositioning of other teeth (incisors, cuspids and bicuspids) in the patient's mouth.
The palatal bar is used in the upper or maxillary dental arch, and is positioned within the arch to be mounted on and extend between the left and right upper molars. The specific teeth are typically the first permanent molars which erupt years before the second permanent molars, but the palatal bar can be used on any reasonably erupted pair of molars. The bar has an upwardly arched central or bridging portion which generally follows the curvature of the hard palate to avoid tongue interference. The central bridging portion is integrally connected between palatal-bar terminal ends which are engaged in brackets (typically welded to tooth-encircling metal bands) mounted on the lingual or tongue-facing surface of the molars.
The application and general function of palatal bars is known, and is described in greater detail in my U.S. Pat. No. 4,408,989, and in, for example, U.S. Pat. Nos. 3,792,529 and 4,582,725. For brevity, these general concepts will not be here restated, and the disclosures of the aforementioned patents are incorporated herein by reference.
An important and growing orthodontic method is so-called lingual treatment where orthodontic brackets and associated arch wires are mounted on the inner or lingual surfaces of the teeth. This technique is especially appealing to teenage or adult patients, because the brackets and wires are largely concealed by the teeth and are not plainly visible during smiling. The palatal bar is inherently a lingual device and is a useful component in carrying out a lingual treatment program. The bar, however, is also useful when applied in a treatment program using conventional brackets and arch wires on the outer or buccolabial tooth faces.
Two problems, both overcome by the present invention, are presented by known palatal bars and associated brackets used in lingual treatment. First, the molar brackets to which the palatal-bar ends are secured should also receive a lingual arch wire which spans the upper dental arch and applies corrective force to teeth anterior of the molars. It is necessary to remove and adjust (or replace) the arch wire as treatment progresses, and prior-art brackets typically require painstaking and time-consuming removal and replacement of the palatal bar to gain access to the arch wire.
The second problem is that known bars and brackets are engaged by movement of the bar ends in a mesiodistal direction (generally parallel to the occlusal plane defined by the exposed tooth ends, and in the direction of the adjacent dental arch) into some kind of mating socket or slot in each bracket. This kind of movement is made difficult by the small available space within the upper dental arch, and by interference of the disengaged palatal bar with lingual brackets or similar appliances on teeth (especially bicuspids) anterior of the molars.
The bracket and palatal bar system of this invention overcomes both of these problems. The bracket provides separate slots or sockets for the palatal bar and arch wire, and is arranged so these components are separately ligated, and are separately removable without disturbing the other component. The bracket and bar are also configured so the bar terminal ends can be engaged and locked to the molar brackets by upward (rather than forward or rearward) movement of the bar within the upper arch beneath the palate, thereby avoiding interference with appliances already installed on teeth anterior to the molars.